Transmission damping apparatus and method

Abstract

The present invention provides a damping apparatus and/or method for a rotatable shaft. The damping apparatus includes a damper housing disposed about a portion of the rotatable shaft. A variable viscosity fluid, such as a magneto-rheological fluid, is disposed within the damper housing and in contact with the rotatable shaft. A control device is operatively connected with respect to the variable viscosity fluid. The control device is configured or operable to control the viscosity of the variable viscosity fluid and correspondingly control the amount of rotational resistance applied to the rotatable shaft.

1 . A damping system for a rotatable shaft, said damping system comprising: 
 a damper housing disposed about a portion of the rotatable shaft;    a variable viscosity fluid disposed within said damper housing operatively associated with the rotatable shaft; and    a control device operatively connected with respect to said variable viscosity fluid, said control device being operable to control the viscosity of said variable viscosity fluid and correspondingly control the amount of rotational resistance applied to the rotatable shaft.    
     
     
         2 . The damping system of  claim 1 , wherein said variable viscosity fluid is magneto-rheological fluid.  
     
     
         3 . The damping system of  claim 1 , wherein said variable viscosity fluid is electro-rheological fluid.  
     
     
         4 . The damping system of  claim 2 , further comprising a magnetic device operatively connected to the control device, said magnetic device being configured to produce a variable strength magnetic field within the magneto-rheological fluid and thereby selectively alter the viscosity thereof.  
     
     
         5 . The damping system of  claim 1 , further comprising a fin mounted to the rotatable shaft configured to increase the drag transferred to the rotatable shaft when contacted by the variable viscosity fluid.  
     
     
         6 . The damping system of  claim 1 , further comprising a seal disposed within a seal groove defined by said damper housing, said seal being configured to prevent the loss of the variable viscosity fluid within the damper housing.  
     
     
         7 . The damping system of  claim 1 , wherein said rotatable shaft is a countershaft.  
     
     
         8 . A damping system for a transmission having a rotatable shaft, said damping system comprising: 
 a damper housing disposed about a portion of the rotatable shaft;    magneto-rheological fluid disposed within said damper housing and operatively associated with the rotatable shaft;    a magnetic device disposed in close proximity with respect to said magneto-rheological fluid, said magnetic device being operable to selectively produce a variable strength magnetic field within the magneto-rheological fluid to alter the viscosity thereof; and    a control device operatively connected to the magnetic device, said control device being operable to control the strength of the magnetic field produced by the magnetic device to thereby control the viscosity of the magneto-rheological fluid such that the amount of rotational resistance applied to the rotatable shaft is variable.    
     
     
         9 . The damping system of  claim 8 , further comprising a fin mounted to the rotatable shaft configured to increase the drag transferred to the rotatable shaft when engaged by the magneto-rheological fluid.  
     
     
         10 . The damping system of  claim 9 , further comprising a seal disposed within a seal groove defined by said damper housing, said seal being configured to prevent the loss of the variable viscosity fluid within the damper housing.  
     
     
         11 . The damping system of  claim 10 , wherein said rotatable shaft is a countershaft.  
     
     
         12 . A method for damping a rotatable shaft of a transmission comprising: 
 providing a magneto-rheological fluid operatively associated with said rotatable shaft;    generating a variable strength magnetic field within the magneto-rheological fluid to alter the viscosity thereof; and    controlling the strength of the magnetic field to selectively alter the viscosity of the magneto-rheological fluid such that the amount of rotational resistance applied to the rotatable shaft is variable.    
     
     
         13 . The method of  claim 12 , further comprising providing a damper housing to retain the magneto-rheological fluid in contact with the rotatable shaft.  
     
     
         14 . The method of  claim 13 , further comprising providing a fin mounted to the rotatable shaft configured to increase the drag transferred to the rotatable shaft when engaged by the magneto-rheological fluid.